Metric
(ISO 7380) A rounded, dome-like head. Used for aesthetics or where a sharp hex edge might snag on something.
| Thread Designation | Head Diameter (mm) | Head Height (mm) | Clearance Hole (mm) | Thread Pitch (mm) |
|---|---|---|---|---|
| M2 | 3.5 | 1.1 | 2.4 | 0.40 |
| M2.5 | 4.5 | 1.3 | 2.9 | 0.45 |
| M3 | 5.7 | 1.65 | 3.4 | 0.50 |
| M4 | 7.6 | 2.20 | 4.5 | 0.70 |
| M5 | 9.5 | 2.75 | 5.5 | 0.80 |
| M6 | 10.5 | 3.30 | 6.6 | 1.00 |
| M8 | 14.0 | 4.40 | 9.0 | 1.25 |
| M10 | 17.5 | 5.50 | 11.0 | 1.50 |
| M12 | 21.0 | 6.60 | 13.5 | 1.75 |
| M14 | 25.0 | 7.80 | 15.5 | 2.00 |
| M16 | 28.0 | 8.80 | 17.5 | 2.00 |
| M20 | 35.0 | 11.00 | 22.0 | 2.50 |
| M24 | 42.0 | 13.50 | 26.0 | 3.00 |
Imperial
Button Head screws following the ASME B18.3 standard.
| Thread Designation | Head Diameter (in) | Head Height (in) | Clearance Hole (in) | Threads Per Inch (TPI) |
|---|---|---|---|---|
| #4-40 | 0.213" | 0.059" | 0.128" | 40 |
| #6-32 | 0.262" | 0.073" | 0.149" | 32 |
| #8-32 | 0.312" | 0.087" | 0.177" | 32 |
| #10-24 | 0.361" | 0.101" | 0.204" | 24 |
| 1/4"-20 | 0.437" | 0.132" | 17/64" | 20 |
| 5/16"-18 | 0.547" | 0.166" | 21/64" | 18 |
| 3/8"-16 | 0.656" | 0.199" | 25/64" | 16 |
| 1/2"-13 | 0.875" | 0.265" | 17/32" | 13 |
| 5/8"-11 | 1.000" | 0.331" | 21/32" | 11 |
| 3/4"-10 | 1.312" | 0.397" | 25/32" | 10 |